Worldwide Motor Company Promised to Buy All Its Needs,"taking into Account

Worldwide Motor Company promised to buy all its needs,"taking into account tires purchased from other tire companies," for automobile tires from Good Tire Co.,and Good promised to sell these tires.The contract also provided that Worldwide could cancel the contract at any time,without penalty,and could buy tires from other manufacturers if it so desired.This contract is:

A) valid and fully enforceable
B) unenforceable,because requirement contracts are generally unenforceable
C) unenforceable,because Worldwide's promise is illusory and there is no mutuality of obligation
D) unenforceable,because output contracts are generally unenforceable